Perhaps you should try some spelling variations:
optimization algorithms » optimisation algorithm, estimation algorithms, estimation algorithm
over optimization » _ optimization
game optimization » stage optimization, market optimization, _ optimization
qoe optimization » _ optimization, stage optimization, _ optimisation

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( over optimization algorithms ) or ( ((game optimization) OR (qoe optimization)) algorithm ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( over optimization algorithms ) OR ( ((game optimization) OR (qoe optimization)) algorithm ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( over optimization algorithms ) or ( ((game optimization) OR (qoe optimization)) algorithm ))*".